Valve for refrigerating medium evaporators



Feb. 13, 1962 J. A. l. BRANDIN 3,020,729

VALVE FOR REFRIGERATING MEDIUM EVAPORATORS Filed Dec. 50, 1958 CEXPANSION L QU/D ONDENSER VALVE SEPHRA roe Fly. 1

' HOT 6445 F0]? 5 FFE C T lNG DEFFOST/NG COMPRESSOR smpaenrok FLOW OFesFe/ssenA/r DUEI-5 F255 Z/NG PER /00 FLOW 0F BEFEIGEEHNT OUR/N5 9 ST/NGFEE/o0 -9- United States Patent 3,020,729 Patented Feb. 13, 1962 ice3,020,729 VALVE FOR REFRIGERATENG MEDIUM EVAPORATORS Johan Axel IvarBrandin, Hogalidsvagen 8, Finspong, Sweden Filed Dec. 30, 1958, Ser. No.783,816 Claims priority, application Sweden Jan. 13, 1958 Claims. (Cl.62-218) In certain types of refrigerating medium evaporators and moreparticularly in so called tube ice generators an ntermittent defrostingis required at comparatively short intervals. Said defrosting operationis effected, as a rule, by expelling the liquid refrigerating mediumfrom the evaporator by means of a hot gas derived from the high pressureside of the refrigerating system. In order that the defrosting operationmay be rapid and efficient, the pipe through which the liquid isexpelled from the evaporator should be blocked up at the very instantwhen all the liquid is removed from the evaporator.

The present invention has for its object to provide a valve for use inconnection with a refrigerating medium evaporator with a View toautomatically blocking up a refrigerating medium pipe after therefrigerating medium is expelled from the evaporator in connection witha defrosting operation.

The invention is characterized, chiefly, by the provision within areceptacle having inlet and outlet pipes for the refrigerating medium,of an open basin which, when the refrigerating medium has been expelledfrom the evapo rator, raises and blocks the pipe through which therefrigerating medium is expelled from the receptacle.

The invention is illustrated by way of example in the accompanyingdrawing in which,

FIG. 1 is a longitudinal section of a receptacle with the valve in openstate and FIG. 2 is a similar section with the valve in closed state.

In the drawing, the numeral 1 designates a closed receptacle for arefrigerating medium, said medium being supplied to the receptacleduring the cooling periods through a pipe 2 from a receiving container,which is situated on a level above that of the evaporator of therefrigerating plant. From the receptacle 1 the refrigcrating medium ispassed to the evaporator through two symmetrically arranged pipes 3 and3. Provided below pipes 2 and 3 is a valve in the shape of a basin 4 theconcave surface of which faces said pipe. Said basin is supported by aset screw 5 and to this end the bottom of the basin is formed with anupstanding sleeve shaped portion 6 into which the upper end of the setscrew projects. The set screw is threaded at 7 and engages by itsthreaded portion a nut shaped sleeve 9 rigidly inserted in the bottom ofthe receptacle 1. Thus, by adjusting the screw 5 the distance betweenthe basin and the pipes may be varied. The numeral 8 indicates a pipefor condensate.

During the cooling periods refrigerating medium is supplied to theevaporator from the refrigerating medium container through pipe 2 andwithdrawn through pipes 3 in the position of basin 4 shown in FIG. 1, sothat the receptacle 1 is completely filled with refrigerating medium.When the evaporator is to be defrosted (including, for instance, removalof icicles from the tubes of an ice machine) a hot gas is admitted tothe evaporator from the high pressure side of the refrigerating machine,said gas expelling the refrigerating medium from the evaporator throughpipes 3, receptacle 1 and pipe 2 up into the refrigerating mediumcontainer at a high velocity. In this operation due to the Venturieffect of fast moving liquid, a vacuum will exist at the entrance ofpipe 2, said vacuum tending to raise the basin 4, thereby causing it toclose the inlet of pipe 2. In order to counteract this tendency thebasin so that the streams of liquid therethrough will be directedtowards the basin, thereby keeping the basin in its open state as longas liquid is discharged from pipes 3. A suitable adjustment of theposition of the basin when open may be fixed by means of the set screw5. By the provision of two pipes 3 symmetrically positioned withrelation to the basin 4 the basin may be symmetrically acted on by theliquid streams.

After the evaporator is emptied of liquid and a gas is allowed to enterthe receptacle 1, the basin 4 will move upwards until it closes theinlet of pipe 2. Said closing action is caused, in part, by the factthat the gas is not in the same way as the liquid supplied through pipes3 capable of counteracting the vacuum as caused by the entrance of therefrigerating medium into pipe 2 and, in part, due to the fact that adifference in pressure will appear because there is a liquid below thebasin and a mixture of gas and liquid above the basin. Due to thedifference in specific weights which exists between said two fluids thebasin will be subjected to a raising or floating power. The positionshown in FIG. 2 will result very rapidly as soon as gas enters into thereceptacle 1.

During the defrosting operation any condensate re sulting will bedischarged from the evaporator through pipes 3 and delivered to thebasin from where it is withdrawn through pipe 8 and delievered to therefrigerating medium container.

After the defrosting operation is ended and high pressure gas is nolonger supplied to the evaporator, the pressure prevailing inside thereceptacle 1 is reduced, allowing the basin to drop under the combinedaction of the weight of the liquid in pipe 2 and its own weight.

I claim:

1. A valve for use in a refrigeration system in which, during defrostingperiods warm ga is caused to flow through the evaporator of the systemin the direction opposite to that in which the cooling medium flowsduring a refrigeration period so that the liquid cooling medium isdriven from the evaporator during the defrosting period and stored in areceiving container connected in a conduit between the condenser andevaporator of the refrigeration system, comprising a closed receptacleconnected in conduits between the receiving container and theevaporator, said closed receptacle having an upwardly open basin-shapedvalve located therein and freely movable in the vertical direction, theconduit between the evaporator and said closed receptacle extending intosaid basin-shaped valve in the downward direction and having egressmeans arranged symmetrically with respect to the center of saidbasin-shaped valves, the imaginary plane extending through said agressmeans being parallel to the bottom of said basin-shaped valve, saidvalve in its uppermost position closing the conduit to said receivingcontainer, while leaving a small play between itself and the egressmeans of the conduits leading to the evaporator.

2. In a valve as claimed in claim 1, the further feature that theconduit connecting said closed receptacle to the, receiving containerhas its bottom end located centrally with relation to the basin.

3. A valve as claimed in claim 1, and in which the conduit connectingsaid closed receptacle to the refrigerant receiving container openscentrally above the basin, and the egress means of the conduitsconnecting said closed receptacle to the evaporator of the system iscomprised of a plurality of downwardly directed open ends positionedsymmetrically on opposite sides of said cen trally positioned conduitend.

4. A valve as claimed in claim 1, and in which means are provided incombination with the closed receptacle containing the basin foradjusting the distance between References Cited in the file of thispatent UNITED STATES PATENTS Mojonnier May 18, Stiren Aug. 26,Schliemann Aug. 4, Kellog Oct. 13, Philipp June 1, La Porte Jan. 4,

